618691 has 4 divisors (see below), whose sum is σ = 622000. Its totient is φ = 615384.

The previous prime is 618679. The next prime is 618703. The reversal of 618691 is 196816.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (618679) and next prime (618703).

It is a cyclic number.

It is not a de Polignac number, because 618691 - 2¹¹ = 616643 is a prime.

It is an Ulam number.

It is a Duffinian number.

618691 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (618671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1356 + ... + 1753.

It is an arithmetic number, because the mean of its divisors is an integer number (155500).

2⁶¹⁸⁶⁹¹ is an apocalyptic number.

618691 is a deficient number, since it is larger than the sum of its proper divisors (3309).

618691 is a wasteful number, since it uses less digits than its factorization.

618691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3308.

The product of its digits is 2592, while the sum is 31.

The square root of 618691 is about 786.5691323717. The cubic root of 618691 is about 85.2101375081.

Subtracting from 618691 its reverse (196816), we obtain a cube (421875 = 75³).

The spelling of 618691 in words is "six hundred eighteen thousand, six hundred ninety-one".